We have the technology to take archived video and enhance it, to make details more apparent than they were in the original. Necessarily, the emotional impact is increased.
If you see a human shot from a distance, he has been shot and your mind remembers that. If you see a human shot from a nearer range, the image is more settled in your brain. Perhaps you saw the body move before it fell. If you see a human shot from a close range, the image left in your head can be strongly details. It's hard to forget details like flying bits of flesh.
I was not around for the assassination of President john F. Kennedy. I didn't watch it live on TV, or on the replays. I wasn't there at Lyndon Johnson's swearing-in, where Jacqueline Kennedy still wore her blood- and brain-splattered suit.
I've see the Zapruder footage, but it did not have the level of graphic impact that the video below made from the Zapruder footage had.
I'm not saying that the enhancement should not have been made. It shows details in a clarity that the original footage did not provide. And yet it is less suitable for airing than the original, precisely because of its level of detail.
The images in this video are extremely graphic. It shows, in full color, JFK's head exploding and parts of his skull and brain flying out. If you have trouble after having watched this video, you should know that studies suggest that playing a visually-intensive game such as Tetris is a good way to prevent PTSD. Here is a game of Tetris.
A mirror of the video is available at rmirror.net, should YouTube remove the above video.